<!DOCTYPE html>
<style>
.fixed {
  position: fixed;
}

.sticky {
  position: sticky;
  top: 0;
}

.composited {
  /* Force compositing without creating a stacking context */
  backface-visibility: hidden;
}

.spacer {
  height: 2000px;
}

.container {
  width: 500px;
  height: 500px;
  overflow: scroll;
}
</style>

<div class="composited fixed">
  Ref text.
  <div class="composited container">
    <div class="sticky">
      This line should line up with the text above.
    </div>
    <div class="spacer"></div>
  </div>
</div>

